Model Output Discussion - Into November 2019

[feb1991blizzard]

A few colder members in the GEFS suite.

[northwestsnow]

6 minutes ago, feb1991blizzard said:

I think we really do need to see that scandi high hold and hopefully combined with a ridge into the pole from the pacific side, as an SSW pre-cursor pattern.

Yes,i'm not really seeing evidence that it will,for the discussions surrounding the disconnect between SPV and TPV there sure looks to be tons of energy in the Jet and frankly, too much for any block to hold to the NE...

Of course it may change in the coming days,but as it stands, i'm thinking we might begin to see some pretty uninspiring charts appearing over the coming days..

Hope i'm wrong mind.

Edited November 11, 2019 by northwestsnow

[feb1991blizzard]

1 minute ago, northwestsnow said:

Yes,i'm not really seeing evidence that it will,for the discussions surrounding the disconnect between SPV and TPV there sure looks to be tons of energy in the Jet and frankly, too much for any block to hold to the NE, as it stands.

Of course it may change in the coming days,but as it stands, i'm thinking we might begin to see some pretty uninspiring charts appearing over the coming days..

Hope i'm wrong mind.

It is holding on the GEFS _ just about - weakening yes but you would expect that on a mean at that range. its just not likely to do what most on here want it to do in the shorter term - deliver a frigid beast into the UK!

[damianslaw]

3 minutes ago, northwestsnow said:

Yes,i'm not really seeing evidence that it will,for the discussions surrounding the disconnect between SPV and TPV there sure looks to be tons of energy in the Jet and frankly, too much for any block to hold to the NE...

Of course it may change in the coming days,but as it stands, i'm thinking we might begin to see some pretty uninspiring charts appearing over the coming days..

Hope i'm wrong mind.

By late November, significant cold pooling can develop quickly to our NE, but I agree in the earlier part of the winter season scandi blocks have a far harder time fighting off the atlantic than they do come mid-latter part of winter, say from mid January onwards when the atlantic traditionally quietens down a bit. They do sometimes win the battle though, think 1995, 1996, 2009, 2010..

Interesting to note current NAO forecasts are for it to go negative rather than stay positive.

Also jetstream profile for the foreseeable remains on a very southerly track.

Many short-term immediate developments would be conducive to a colder pattern rather than a milder one setting up as we end November, but as we know things can often switch, and usually do so latter end to November start to December.

 

 

[Allseasons-Si]

3 minutes ago, feb1991blizzard said:

It is holding on the GEFS _ just about - weakening yes but you would expect that on a mean at that range. its just not likely to do what most on here want it to do in the shorter term - deliver a frigid beast into the UK!

I wouldn't look at the mean +ten  days>,at day ten max

even day ten is pushing it but here it is

look at that curve of cold uppers into Scandi on the 850's,this is what i will be looking at in future.

 

[northwestsnow]

I agree with you Damien...

I think what is giving me the wobbles is the Glosea update tonight, coupled with the EC monthly...

Both suggestive of a +NAO setup..

Added to that the last two GFS runs have trended this way, and so too,IMO has the EC det.

I am most certainly not writing off Dec, but i am saying alarm bells are beginning to ring that the last third of Nov might go zonal.

 

[feb1991blizzard]

2 minutes ago, Allseasons-si said:

I wouldn't look at the mean +ten  days>,at day ten max

even day ten is pushing it but here it is

 

look at that curve of cold uppers into Scandi on the 850's,this is what i will be looking at in future.

 

Second chart interesting to be fair.

[Kirkcaldy Weather]

On 05/11/2019 at 15:05, Kirkcaldy Weather said:

 

MJO moved briefly into phase 4 during the last days of October https://1316da03-e6e5-4264-d4a8-7d2a1b50b5ed.filesusr.com/ugd/31d9e0_b438a5126b4cf5a32f67041512156dad.pdf again this suggests higher pressure to the N / NE and lower pressure to the south so the possibility of an easterly (which some ensembles have hinted at recently) and as I have mentioned with cold conditions across Scandi should we get an easterly I wouldn't rule out the chance of some wintry conditions.

 

Will do a more in depth update as things progress but just a few things I am monitoring. Looks like a key period around 18th / 19th November onward with regards to possible easterly and looks like developments centered around areas of lower pressure and their movements latest GFS op -  moves it N /NW cutting off the chance of the easterly developing GFS 00Z and ensembles   

 keeping lower pressure to the S / SW giving us a better chance of getting the easterly flow, yes we would still need the scandi high to align favourably but another thing worth monitoring are any cold pools developing to the east / north east  

So I would say we are still 50/50 whether we get an easterly (and any accompanying wintry possibilities) and just for reference you dont always need deep cold the November 2010 snowfall event here had 850 temps of -8  and another thing worth remembering is how often we have seen the models during previous cold spells usually have a tendency to try and break down the blocking areas of high pressure at least a few days too quick underestimating the strength. 

[SLEETY]

Regarding the glosea  model well it got the Autumn completely wrong regarding temps.Went above average for the ,3 months and  2 of them are going to be below normal,so the complete opposite, lol

[Geordiesnow]

All a little messy the output even though the general trend in terms of temperatures is pretty consistent of cool/chilly but not overly cold and certainly no mild weather on the horizon. 

No surprises the Atlantic ridge never ridged into Greenland, was not really modelled and the usual marginal watering down of the Atlantic ridge has occured as yet again, far too much energy is leaving newfoundland so any ridge is struggling to maintain itself. 

Will it turn somewhat drier for the weekend? No doubt if we get any weak heights, the nights will be cold and more than likely frosty given the fairly cool uppers and low thicknesses. For now though, its an unsettled outlook with a small respite on Wednesday before that potentially slow moving front for parts of England come Thursday onwards. 

[Robbie Garrett]

5 minutes ago, northwestsnow said:

I am most certainly not writing off Dec, but i am saying alarm bells are beginning to ring that the last third of Nov might go zonal.

There's one thing that strikes me on the latest MO updates, and they've put one interesting caveat on it.

"Through the second half of November and into December, confidence remains low."

Either way, interesting pattern building next week.  The jet seems to be pivoting under the high over Europe, and surely that's what you want?

 

 

Be interested to see if the models can get to grips with that Afghan/Euro High.

[Allseasons-Si]

@Kirkcaldy Weather

I was just about to comment on this regards to the Atlantic breaking through 

while there is a block to our east or NE the systems/troughs or lows will have a bit of a hard time breaking through the meridian aka the UK 

even the ecm doesn't manage this even though it seemed a bad run we still see blocking to the E/NE,it's all variants of the theme but the overall theme is still the same IE-

blocking to our N/NE or east

how many times have we seen the FL outputs blow the block away to find out a few days later that the systems are still stalling out to our west,i am not saying this will happen this time but we ponder on this all the time

so if you see models blow the block away in FL,DON'T BELIEVE IT.

 

 

 

 

 

 

[Bruegelian]

Seriously, has GLOSEA updated for this month?  The latest month still seems to be October for me.

[northwestsnow]

1 minute ago, Bruegelian said:

Seriously, has GLOSEA updated for this month?  The latest month still seems to be October for me.

Yes.

Its unchanged from previous ..

[Cheshire Freeze]

1 hour ago, Jonathan Rhodri Roberts said:

Doesn't that chart mean higher pressure though so we could finally see a gradual drying out process from December after several weeks of very wet weather? 

Looks like 88/89 to me. Suggests maybe some record breaking winter warmth.

[feb1991blizzard]

1 minute ago, CreweCold said:

Looks like 88/89 to me. Suggests maybe some record breaking winter warmth.

Could suggest some record breaking river levels in Dec as well.

[knocker]

A quick glance at the EC weekly update for the first half of December

The first week indicates a split vortex with the main lobe northern Canada divided to some extent by a Alaskan ridge. A strong westerly upper flow exiting the eastern seaboard abating a tad in the east courtesy of some positive heights in the east and low pressure around the Mediterranean. Ergo still changeable (perhaps tending to N/S split with temps around average.

Rather more emphasis on the Canadian vortex trough in the second week which, coupled with the loss of positive heights to the east, results in the Atlantic having rather more influence which portends weather remaining changeable with temps above average

[knocker]

The North Atlantic 500mb and surface analysis for midnight

The low is now centred in the North Sea but a couple of bands of rain associated with the fronts are currently effecting areas in the north whilst showers persist in western coastal regions further south. These bands will move east and south during the day, the rain quite heavy for a time over Wales accompanied by some quite strong winds, falling as snow over the high ground.

the rain and showers will die out tonight apart from down western coastal regions but under clear skies quite a severe frost in the north by Wednesday morning

So a bright start to Wednesday but cloud will ingress from the west with showers pepping up a tad in that region, but the next low pressure with associated fronts is tracking in from the north west and these will bring rain to N. Ireland, Wales (snow on the high ground) and the south west by late afternoon/early evening.

Over Wednesday night and through Thursday events upstream (previously discussed) amplify the downstream ridge which in turn re-orientates the trough over the UK. All of which results in the low and surface fronts tracking south east across the bottom half of the country resulting in some quite prolonged and heavy rainfall in some areas.

The pressure from the west and the re-orientation will continue on Friday as the rain band slowly moves south east but still quite a wet day in many central and south eastern areas

A better day on Saturday as the front and rain do finally clear to the south east but another frontal system is sneaking east west of Ireland. And away over on the eastern seaboard an extension of the vortex is tracking into the Atlantic

Edited November 12, 2019 by knocker

[Ali1977]

Greeny height showing up again in the Op, lots of ENS have been showing this towards the last week of Nov. Maybe that would be better than a Scandy high with the lack of cold close to our East. All FI, and I’m sure we’ll be none the wiser after today or even tomorrow 

[SLEETY]

Do not like the look of the runs this morning ,just appears to be an extension of the current weather,with copious amount of rain for many areas,with a fair bit of flooding to go with it too.

Getting concerning now,and snow looks like being confined to the high hills only.

Not much in the way of very cold weather in the extended GFS either

[knocker]

According to the gfs what happens over Sun > Tues is complex to say the least'

On the one hand there is the very strong eastern block and on the other rapid cyclogenisis again taking place in the north west Atlantic and to my eye it's the energy distribution between and around these systems which is causing a bit of head scratching.

On the surface all of this results in not a bad day on Sunday although the front does make some headway in the west; By Monday the low to the south east has become reinvigorated and is tracking north up the North Sea whilst the conduit to the north west is reestablished; And by Tuesday a low has traveled down this. Of course all of this should be treated with much caution

Edited November 12, 2019 by knocker

[tinybill]

looking at the  gfs from now  to lala  land their some horror charts for the flooded  areas   ,just the rain  keeps coming no end in sight

[Ali1977]

Not all bad news, some cracking “colder” ENS at day 10 with this mean.

Edited November 12, 2019 by Ali1977

[Chesil View]

So this morning's 0z GFS op not as exciting as yesterday's at the same time. However more of the ensembles go cold in the medium term compared to this time yesterday. So perhaps a steadily growing trend towards something wintry.

[knocker]

Looking at the 5-10 GEFS mean the conduit from the vortex to south of the UK looks reasonable but the diverging flow complicates the surface analysis

The ext GEFS this morning, although still indicating positive anomalies in the eastern Arctic/N. Russia has the ridge a tad more aligned to the N/NE of the UK. This still leaves us with diverging upper winds with the UK virtually in a col and the conundrum of the surface analysis.

Edited November 12, 2019 by knocker